Accumulated - doing accumulated 12 months for every month of the axis x

I'm trying to create accumulated measure but I'm not getting it. Actually it's a different accumulation, since I want it to show me on the x axis the last 6 months and the value of each month is the accumulated 12 months back.

ex:

the X Axis contains 6 months (June / 18, July / 18, August / 18, September / 18, October / 18, November / 18). The value that will show in June / 18 is the sum of July / 17 until June / 18 (last 12 months), the amount that will show in July / 18 is the sum of August / 17 until July / 18 (last 12 months) and so on. That is, each month it makes the accumulated 12 months back. can you help me?

I have attached a file to make it base to make the formula. I put a page filter with a relative date of the last 6 months, but I can not do this accumulation.